It is known that in engines having removable wet cylinder liners, the upper part of the body of the liner ends in a flange, generally topped by a slightly raised rib. The level of the upper part of said rib or said flange defines a slight oversize with respect to the level of the top part of the block into which the liner is nested. The assembly is then covered by a flat gasket which is topped by a cylinderhead. The cylinderhead is tightened by means of screws, each of which has a stem passing through the cylinderhead, the cylinderhead gasket, and a hole tapped in the cylinder block for the fixing or fastening thereof. Several set screws are thus distributed around each cylinder of the engine. In order to make the explanations clearer, this known disposition is illustrated in the FIGS. 1 to 5 appended hereto.
FIG. 1 shows a cylinder block 1 the flat upper part 2 of which includes a number of housings 3. In each of said housings a liner 4 is inserted, the top of which defines a flange 5. Said flange is topped, for instance, by two raised ribs 6 and 7. Said ribs are concentric, being centered on the axis of the liner 4.
After the liners are mounted in the cylinder block 1, it will be seen that the ribs 6 and 7 project slightly above the plane of the part 2.
As is known, a flat gasket 8 is then disposed over said top 2, and then the assembly is topped by a cylinderhead which can be either an individual cylinderhead 9, or a cylinderhead 10 for several cylinders (FIG. 1).
The tightening is made by means of screws such as the screw 11. Owing to the raised positions of the ribs 6 and 7, it will be seen from FIG. 5 that tightening each of the screws 11 tends to bring about the following deformations:
A rocking of the flange 5 with respect to the bearing thereof on the cylinder block 1, that is, a swelling of the body of the liner 4, as indicated by the arrow 12; PA1 A depression in the bearing top part 2 in the area 13 in close vicinity to the flange 5; and PA1 A deformation of the bearing surface of the cylinderhead 9 in the area 14.
These deformations bring about various drawbacks, the worst of which is the swelling 12 of the liner 4, all the more so as said swelling is not uniform all around the axis of the bore.
One object of the present invention is to obviate said drawbacks by providing an arrangement which, while ensuring a correct fluid-tightness for the liner 4 at the level of the ribs 6, 7, allows to removal any secondary deformation and maintains the accurately cylinderical shape of the inner surface of said liner 4.